Quick answers
- Does Donald L. Whisler accept Medicare assignment?
- Yes. Medicare's clinician data says Donald L. Whisler accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
- How many Medicare patients does Donald L. Whisler see?
- In 2024, CMS data shows 457 Original Medicare patients and 7,531 services for Donald L. Whisler. This counts Original Medicare only and measures volume, not quality.
- What is Donald L. Whisler's NPI number?
- 1639516149. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Medicare activity in 2024
Official CMS public-use data for Donald L. Whisler, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.
| Original Medicare patients | 457 |
|---|---|
| Services billed to Medicare | 7,531 |
| Different services or procedures | 23 |
| Participating Medicare provider | Yes |
| Average age of these patients | 73 |
Most frequent services
- Injection, denosumab, 1 mg (J0897)3,360 services
- Injection, methylprednisolone acetate, 1 mg (J1010)1,200 services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)600 services
- Visit complexity inherent to evaluation and management associated with medical care services that serve as the continuing focal point for all needed health care services and/or with medical care services that are part of ongoing care related to a patient's (G2211)573 services
- Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)103 services
Chronic conditions among these patients
Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).
- Arthritis75%
- High cholesterol72%
- High blood pressure63%
- Anxiety28%
- Osteoporosis26%
- Depression25%
Hospitals where Donald L. Whisler works
Medicare's Facility Affiliation Data lists Donald L. Whisler at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.
- Healdsburg HospitalHealdsburg, CA · Critical Access Hospital · Emergency services: listed by Medicare · CCN 051321
- Mad River Community HospitalArcata, CA · Acute Care Hospital · Medicare rating: 1 of 5 stars · Emergency services: listed by Medicare · CCN 050028
- Providence Queen of the Valley Medical CenterNapa, CA · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 050009
- Providence Santa Rosa Memorial HospitalSanta Rosa, CA · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 050174
- Providence St Joseph HospitalEureka, CA · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 050006
Practice locations
Addresses where Donald L. Whisler is enrolled with Medicare (CMS data updated October 2, 2026).
- 500 Doyle Park Dr, Suite 300Santa Rosa, CA 95405 (707) 303‑8344
Group practices
Medicare enrollment lists Donald L. Whisler as a member of this group (CMS data updated October 2, 2026).
- Providence Medical Foundation1,466 clinicians in the group
Specialties
- Rheumatologyprimary
- Internal Medicinealso
Other rheumatologists in Santa Rosa
Clinicians with the same Medicare primary specialty in Santa Rosa, CA — not a recommendation.
Other clinicians in Providence Medical Foundation
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 2013 (13 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1639516149 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
- Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians